Current rectification effects in 6 nm thick HfxZr1-xOy ferroelectrics/Si planar heterostructures

We show experimentally that current rectification occurs in planar ferroelectric Zr-doped HfO2/Si heterostructures having a thickness of 6 nm. When the applied electric field is sufficiently high, so that the polarization direction in the ferroelectric layer switches, and thus the potential barriers decrease, a strong nonlinear current flows through this ambipolar planar device. Current rectification is therefore achieved, with potential applications in electromagnetic energy harvesting. On illumination with white light, a photoresponse is observed for both bias polarizations.